Air-cooled cylinder



March 14, 1933. Y E. BECKER 11,901,693

' AIR COOLED CYLINDER.

Filed Nov. 19, 1930 Patented Mar. 14, 1933 UNITED STATES PATENT OFFICE HALSKE, AKTIENGESEILSCHAFT, OF SIEMEN'SSTADT CORPORATION OF GERMANY NEAR BERLIN, GERMANY, A.

AIR-COOLED CYLINDER Application fled November 19, 1930, Serial No. 496,685, and in Germany November 19, 1829.

My invention relates to improvements in air-cooled c linders and more particularly to air-cooled cylinders for internal combustion engines.

In the air-cooled cylinders hitherto known, particularly for internal combustion engines the cylinder liner consists of steel, the combustion chamber with its top cover and gas ducts of light-metal alloy. There exist also cylinders in which the top of the cylinder consists also of steel and in which the valve seats are directly placed in the steel top of the cylinder. The latter design has the disadvantage that the exhaust valve seats last only for a comparatively short time as a result of the oor heat-conductivity of the steel. The at cylinder top has, however, the advantage that the four valves, in order to obtain a greater cylinder output, can be arranged with parallel stems, without having therefore to incline the valve spindles to one another, as such is the case with lightmetal heads in consideration of the shrunkin valve seats, which cause an unnecessarily great air resistance.

The invention makes it possible to arrange the four valves with parallel stems and therefore with the smallest air resistance, this advantage not being afiected by the 80 poor heat conductivity of the cylinder top of steel. According to the invention the top of the cylinder is made of a beryllium bronze alloy of great strength and good heat-conductivity. This top contains at the same time the valve seats, whilst the gas ducts are arranged in the light-metal .head, resting on the beryllium top.

The accompanying drawing illustrates an embodiment of the invention. steel liner of the cylinder, 2 the cylinder top of beryllium bronze, which according to the invention is designed in the form of a pot and which is provided with ribs and-thread at the inside and which is screwed on in a heated state; this top contains at the same time the valve seats 3. 4 represents the cylinder head which in this arrangement is relieved of the thermal and mechanical stresses inherent in the previous constructions and which substantially only serves 1 denotes the to guide the gases. -At 5 are shown the cooling ribs of the steel liner 1, and which may be arranged in any suitable manner well known in the art. In the present example they are cut into the solid wall of the steel liner 1.

The advantages of the cylinder consist in the possibility of arranging four' valves on a flat cylinder top, whereby it is possible to obtain an unusually good cooling of the valves as a result of the excellent heat-com ducting qualities of the employed material.

The described combination of the cylinder top of beryllium bronze with the light-metal head has further the advantage, as compared wlth a cylinder top and cylinder head of one piece of beryllium bronze, of a considerable savlng in weight and a considerable reduction in cost.

I claim as my invention:

1. An air cooled cylinder articular] for internal combustion engines, aving a ribbed steel cylinder portion, a cylinder top of a beryllium alloy of high tensile strength and good heat conductivity, shrunk onto one end of said. steel cylinder, and a lightmetal cylinder head attached to said top, said top containing the engine valve seats and said head containing the gas ducts leading to and from said seats. 2. An air cooled cylinder particularly for internal combustion engines, having a ribbed steel cylinder portion, a pot shaped cylinder top of a beryllium alloy of high tensile strength, threaded and shrunk onto one end of said steel cylinder, and a light-metal cylinder head attached to said top, said top containing the engine valve seats and said head containing the gas ducts leading to and from said seats.

In testimony whereof I afiix my signature.

ERNST BECKER. 

